Process for refining oils



or lubricating oils.

Patented May 19, 1953 PROCESS FOR REFINING OILS Robert M.Kennedy,'Newtown Square, and Abraham Schneider, Philadelphia, Pa.,assig'nors to Sun Oil Company, Philadelphia, Pa., a corporation of NewJersey Application July 14, 1950, Serial No. 173,747

22 Claims.

This invention relates to the treatment of hydrocarbons, and moreparticularly to a process for the refining of hydrocarbons.

Many chemical agents, including sulfuric acid, alkalies, fullers earth,boron fluoride, aluminum chloride, and the like, have been described asuseful in the refining of hydrocarbons and mixtures thereof, such aspetroleum, including crude oils and the various petroleum fractionsobtained therefrom. A substantial proportion of refining operations isdirected to the removal of nonhydrocarbons, such as sulfur, oxygen, andnitrogen compounds from crude oil or from various hydrocarbon fractions,such as the gasoline and lubricating oil fractions. For example,mercaptans, sulfides, disulfides, thioethers, and thiophenes are foundin crude oil and the various petroleum fractions, and exert adeleterious effect thereon, such as the formation of color and sludge.Other refining operations are directed to the removal or adjustment ofthe concentration of a hydrocarbon type, such as aromatics, in a givenfraction to prepare a product suitable for specialized uses, such as foruse as transformer For example, concentrated sulfuric acid has been usedas the treating agent. Processes employing this reagent, however, havemany disadvantages: a substantial quantity of the oil is converted to asludge from which neither the sulfuric acid nor a valuable hydro,-carbon product can be obtained, the sludge presents a serious disposalproblem, serious corrosion problems ar encountered, and special treatingof the oil thereafter, such as by clay percolation, is required. Otherprocesses involving the use of agents such as boron fluoride and aprocess for the refining of hydrocarbons, particularly petroleum,including crude oil and the petroleum fractions obtainable therefrom. Afurther object is to provide a refining process wherein only a smallamount of the petroleum hydrocarbons are converted to sludge and a largeimprovement in color, color and oxidation stability, and otherproperties is achieved. Another object is to provide a process for thesimultaneous refining of a mixture of aromatic and nonaromatichydrocarbons and adjustment of the aromatic content to a desired value.A still further object is to provide a process of refining wherein thesludge formed is or may be converted to useful products. Other objectsappear hereinafter.

In patent application Serial No. 38,167, filed July 10, 1948, now PatentNumber 2,557,113, there is described various reactions of hydrocarbonshaving at least one tertiary hydrogen atom per molecule, such'asalkylation, isomerization, and the like, using the present combinationof catalytic components to initiate such reactions, the process beingconducted in th absence of aromatics.

In patent application Serial No. 130,926, filed December 3, 1949, thereis described the alkylation of alkylatable aromatics with saturateshaving at least five carbon atoms and at least one tertiary hydrogenatom per molecule by bringing together a tertiary alkyl fluoride and BFsin the presence of a mixture thereof, the mole ratio of tertiary alkylfluoride to aromatics plus saturates being from 1:20 to 3:5, and themole ratio of saturates to aromatics being from 1:4 to 4:1.

In patent application Serial No. 173,745, filed July 14, 1950, there isdescribed and claimed a process for the separation of non-hydrocarbonsfrom hydrocarbons which comprises bringing to,- gether boron fluorideand a primary or secondary alkyl fluoride in the presence of a mixturethereof, whereby a sludge containing the non-hydrocarbons is formed. Inthis process, if the quantity of alkyl fluoride used is in excess of thequantity required to remove the non-hydrocarbons, the aromatics areconverted to and form a portion of the sludge, but only aftersubstantially complete removal of the non-hydrocarbons.

In patent application Serial No. 173,746, filed July 14, 1950, there'isdescribedand claimed a process for the separation of aromatichydrocarbons from saturated non-aromatic hydrocarbons by bringingtogether a primary or secondary alkyl fluoride in the presence of amixture thereof, whereby the aromatics are converted to and separate asan insoluble sludge,

In patent application Serial No. 173,748, filed July 14., 1950, there isdescribed and claimed a process for separating non-alkylatable aromatichydrocarbons from saturated non-aromatic hydrocarbons by bringingtogether boron fluoride and a tertiary alkyl fluoride in the presence ofa mixture thereof, whereby the non-alkylatable aromatics are convertedto and separate as a sludge.

It has now been discovered that by bringing together a tertiary alkylfluoride and SP3 in the presence of a mixture of hydrocarbons and nonhydrocarbons, a catalytic condition is established which is effective toremove the non-hydrocarbons, and that only a small amount of thehydrocarbons are lost in the process; It has been further discoveredthat after selective removal of the non-hydrocarbons, thenon-,allsylatable aromatics may be selectivelyremoved.

In accordance with the present invention, the combination of the presentrefining agents, a tertiary alkyl fluoride and boron fluoride, has beenfound to be extremely potent and highlyiselective for the removal of thenon-hydrocarbon components of oil which form oxidation sludge,components which impart color and cause the formation of color onstanding, such non-hydrocarbon components being, in general, sulfur,oxygen, and nitrogen compounds. After removalof the deleteriousnon-hydrocarbons, the combination of the present refining agents isextremely potent and highly selective for the removal ofnon-.alkylatable aromatic hydrocarbons. Only after removal by sludgeformation of the non-hydrocarbons and aromatics do the reactionsdescribed in aforesaid patent application Serial No, 38,167 occur, andonly after removal of the non-hydrocarbons and in the presence of bothalkylatable aromatics and tertiary hydrogen containing isopara-flins dothe alkylation reactions described in aforesaid patent applicationSerial No. 130,926 occur. Thus, by proper adjustment of theoperating'c-onditions, particularly the concentration of the alkylfluoride, as hereinafter described, deleterious components ofhydrocarbons, and especially of crude oil or the petroleum fractionsobtainable therefrom, ma be removed withoutany substantial loss ofvaluable hydrocarbons. bysludge formation or degradation to undesiredcompounds.

Thus, in accordance with thev present invention, when a tertiary alkylfluoride and boron fluoride are brought together in a mixturev ofnonhydroo'arbons and non-aromatic saturated hydrocarbons, thenon-hydrocarbons are converted to and separate as an insoluble sludge.If nonalkylatable aromatics are present, and if the amount of alkylfluoride employed is in excess of amount required to remove thenon-hydrocarbons, the non-alkylatable aromatics are also converted andseparate as an insoluble sludge, the amount of conversion beingdependent upon the quantity of alkyl fluoride available for thereaction. In the higher boiling petroleum fractions, particularly thelubricating oil fractions, the aromatics present are substantially allnon-alkylatable, and

operation of the present process with such fractions forms a preferredembodiment of the present invention. By thev expression non-alkyla-tablearomatics, as employed herein, is meant the or are composed of highlycondensed aromatic rings with substituents thereon, and the wide varietyof aromatics occurring in petroleum which are readily removable in thepresent process illustrates the versatility thereof. For example, amongthe aromatics that occur in petroleum are the substituted aromatics ofthe benzene, naphthalene tetralin, anthracene, and phenanthrene series,which are removed in accordance with the present process, as may otheraromatics, such as the unsubstituted homologues of the mentioned series,as above described.

The present process is also operable in the presence of alkylatablearomatics. Thus, in accordance with the present process, withalkylatable aromatics present in the aforesaid mixture to be refined,the non-hydrocarbons are first selectively removed, and only after theirremoval do the alkylation reactions as described in patent applicationSerial No. 130,926 occur, and then only when a quantity of tertiaryalkyl fluoride in excess of that required to remove thenonhy-droc-arbons is employed. When such an excess of the fluoride isused, on completion of the alkylation reactions, the so-fcrmednon-alkylatable aromatics are removed as above described. Hence, byproper adjustment of the operating conditions, particularly theconcentration of tertiary alkyl fluoride, as hereinafter fullydescribed, it is possible to remove non-hydrocarbons, or to removenon-hydrocarbons, convert any alkylatable aromatics to non-alkylatablearomatics, and then remove all or a desired proportion of sucharomatics, together with any non-alkylatable aromatics initialllypresent in the reaction mixture. It should be further noted that in theabsence of tertiary hydrogen containing saturates, no alkylation isobserved, and alkylatable aromatics are converted to sludge the same asnon-alkylatable aromatics.

The saturated non-aromatics from which nonhydrocarbons and aromatics areremoved are the paraflins, including branched chain paraflins, and thecycloparaffins, including naphthenes.

A substantial advantage of the present refining process is that both ofthe components of the refining catalytic combination are soluble inhydrocarbons, thus eliminating the necessity for the vigorous agitationinv processes involving insoluble reagents, such as sulfuric acid,hydrogen fluoride, and aluminum. chloride. It is evident that thepresent reaction mixture forms a homogeneous phase wherein reactionoccurs, and on completion of which the system becomes heterogeneous dueto the formation of a sludge composed of theiun'desirable constituentsof the hydrocarbons. It is characteristic of the present process thatthe alkyl fluoride employed in the process is converted to thecorresponding paraflin.

For example, if t-butyl fluoride is employed, isobutane is formedtherefrom and is a product of the reaction. A further advantage of thepresent process is the instantaneous nature of the present reaction,which occurs and is completed practically as soon as the catalyticcomponents, a tertiary alkyl fluoride and boron fluoride, are broughttogether in the presence of the oilbeing treated. It follows that timeis not a critical variable in the process, and no advantage is obtainedby long periods of contact. For practical convenience, a contact time offrom 1 to 40 min.- utes is suitable.

Hydrocarbons which maybe refined in accordance with the present processinclude crude petroleum and the various fractions obtainable pentane andother t-octyl fluorides.

therefrom, such as gasoline," kerosene, and lubrihydrocarbons which canbe obtained from petroleum, and. mixtures thereof; by crude petroleum ismeant petroleum which has not been separated into fractions, and whichtherefore contains hydrocarbons having widely varying boiling points;and by petroleum fractions, and

fraction, is meant a mixture of hydrocarbons obtained from petroleumhaving a relatively narrow range of boiling points.

Hydrocarbons and mixtures thereof obtained from sources other thanpetroleum may be separated from non-hydrocarbons in accordance with theprocess of the present invention, and likewise may be separated fromaromatics. For example, hydrocarbons prepared by the Fischer-Tropschsynthesis may be separated from non-hydrocarbon constituents, such asoxygen compounds. By the term oil, as used herein, is meant thehydrocarbons and mixtures thereof which may be refined in the presentprocess, as above The concentration of non-hydrocarbons in the oilsrefined in the present process is usually from 0.05 to 2%, althoughhigher concentrations, up to about 5%, may be present in crude oils, andgood results obtainedtherewith. When nonalkylatable aromatics arepresent, the concentration thereof is usually from 1%to 30% by volume.Alkylatable aromatics should not exceed about %"by volume because, insuch case, excessive quantities of alkyl fluoride are required toconvert them to non alkylatable aromatics,

.and a prohibitive quantity of alkylating hydrocarbons are lost.

The'alkyl fluorides which can be employed in the present process are thetertiary alkyl fluorides, i. e., t-hose alkyl fluorides wherein thefluorine atom is attached to a tertiary carbon atom.

A few specific examples of preferred tertiary fluorides are:-2-fluoroe2-methylpropane t-butyl dimethylbutane and other t-hexylfluorides; theptyl fluorides; and 2-fluoro-2,4,4-trimethyl- It will beunderstood that the specific compounds named above are given merely byway of illustration, and

that any tertiary alkyl fluoride will produce an operative catalyticcombination with BE; in accordance with the present invention.

In carrying out the process of the present invention, it is preferred tofirst dissolve the desired amount of alkyl fluoride in the oil, and thenadd the BFs, such as by bubbling it into the solution.

. in separate portions of the oil and then admix the portions, thusbringing together the refining agents in the presence of the oil. It isnot permissible to premix the. alkyl fluoride and BF: since, insuchcase, the catalytic condition requiredto be exerted in the presenceof the hydrocarbons being refined is immediately dissipated. By theexpression bringing together, and terms of similar import, as employedherein in conjunction with the use of the present refining agents, ismeant the actual contacting thereof, .which in the .present process isalways performed in the presence of the oil being refined, i. e., thepresent refining agents, a tertiary alkyl fluoride and boron fluoride,are contacted only when they. are also. in contact with the oil beingrefined.

The degree of refining, i. e., the quantity of non-hydrocarbons, andsubsequently of the aromatics, removed in the process of the presentinvention is substantially dependent upon the quantity of alkyl fluorideemployed. The quantity of boron fluoride to employ is not critical, solong as a quantity sufficient to establish the necessary catalyticcondition is. employed. Since the concentration of sulfur, oxygen,.andnitrogen compounds varies according to the origin of the material beingtreated, and upon prior treatments, if any, it is preferred to determinethe optimum concentration of alkyl fluoride for each application, a suchvalue being readily deter.- minable in view of the presentspecification. It is desired to remove only the non-hydrocarbons, thequantity of alkyl fluoride may be adjusted to so operate, and if it isfurther desired to remove all or a portion of the aromatics, acorrespondingly higher concentration of the alkyl fluoride should beused. In general, a concentration of alkyl fluoride greater thanrequired to remove all of the aromatics, or of all of thenon-hydrocarbons in the event that aromatics are not present in thereaction mixture, should not be used-because, in such case, reactions ofthe tertiary hydrogen containing 'isoparaflins which may be presentoccur, which reactions may materially alter the composition andproperties of the hydrocarbons being treated. A concentration of alkylfluoride of from 0.5 to 2 weight percent is usually suflicient to removesubstantially all of the non-hydrocarbons of a petroleum fraction. If itis desired to subject the fraction to a more drastic treatment inorderto remove aromatics, a greater quantity of the alkyl fluorideshould be employed, say from 2 to 20 weight percent although in someinstances as much as 30 weight percent may be employed. The quantity ofalkyl fluoride, in excess of that required to remove thenon-hydrocarbons, required to remove a desired quantity of aromaticsshould be determined for each application. In general, it has been foundthat 1% by weight of'alkyl fluoride in excess of the amount required toremove non-hydrocarbons will convert about 20% of the aromatics present,and a similar excess of 2.3% will convert about 50% of the aromatics, inboth instances using an excess of boron fluoride. .The separation ofsuch large amounts of aromatics with only small amounts of alkylfluoride is considered a significant advantage of the present process.Equal molar quantitie of the various alkyl fluorides within the scope ofthis invention remove substantially the same quantity of aromatics froma given mixture.

As above stated, the concentration of boron fluoride to employ is notcritical, the requirement being that a quantity suflicient to establishthe catalytic condition be employed. In general,

from 0.1 to 400 weight percent, and preferably small.

7 from :1 to 200 weight percent, based on the weight of alkyl fluorideemployed, is suificient to cause completion of the present refiningprocess 'to the desired extent, which, as above described, is determinedby the :quantity of alkyl fluoride employed.

The present reaction is conducted in the :liquid phase.Super-atmospheric pressure .is preferred so that the desired amount ofboron fluoride readily dissolves in the reaction mixture. Pressures offrom atmospheric to .500 .p. s. i., depending on the concentration ofboron fluoride desired, aresuitable in the case of normally liquidhydrocarbons, whereas a higher pressure, up to 1,000 p. s. i., may beemployed with normally gaseous fractions in order to maintain suchfractions in the liquid state.

The operable temperature range varies considerably and depends largelyon the particular material being treated. A temperature sufiicient- 1yhigh to maintain the hydrocarbons :in a fluid, i. e., non-viscous, stateis'preferred. In general, temperatures of 20 C. to 150 C. may be em-.ployed, and all tertiary alkyl fluorides in combination'with boronfluoride .give good results within this range. If it is desired .tooperate at lower temperatures, such as in the refining of liquifiednormally gaseous hydrocarbons, the lowest temperature at which thepresent fluorides can be employed is 120 C.

As above described, the refining agents are soluble in the present oils,and on completion of the reactions a sludge separates to form aheterogeneous phase. As already described, only a small amount ofhydrocarbons are converted to asludge in the removal ofnon-hydrocarbons, and hence the total quantity of sludge formed is ifaromatics are also converted to sludge, the quantity thereof increasesin accordance with the amount of conversion of the aromatics. The sludgemay be separated by any convenient or desired means, such'as byfiltering, centrifuging or decanting. The oil, after sludge removal, isadvantageously washed with water or an aqueous solution of an alkali,such as sodium hydroxide,

or it may be treated with ammonia. The refined product is obtained byseparating the heterogeneous phase of this last treatment, and ispreferably dried if necessary or desirable. Treatment of the oil withclay, such as is usually required after sulfuric acid refining, is notrequired, but

of course may be employed if desired, as may other process steps asknown to the art.

Boron fluoride and hydrogen fluoride are easily recoverable from thesludge by heating or applying a vacuum, or both. For example, heating toabout 190 C. under a slight vacuum drives ofi hydrogen fiuoride andboron fluoride, which may .be recovered, the boron fluoride beingrecycled to the process and the hydrogen fluoride being used to prepareadditional alkyl fluoride, such as by .an addition reaction with anappropriate :olefin, as known to the art, the resulting alkyl fluoridebeing then employed in the process.

Attention is now directed to the accompanying flow diagram whichillustrates an embodiment of the present invention, and is primarilydirected to the removal of non-hydrocarbons, principally sulfurcompounds, from a saturate petroleum fraction. The hydrocarbons to berefined, a petroleum fraction containing non-hydrocarbons "being-used asillustrative, are introduced into the process-through line I andtertiary butyl fluoride, used to illustrate the various alkyl fluorideswhich may be employed, is introduced into the system through line :2. .Amixture .of the 'petroleum'iraction and tertiary butyl fluoride passesthrough line 3 into heat exchanger 4 wherein the temperatureoftheimixture is adjusted to the desired value, usually from.20 C. to150 C. The mixture then passes :through .line :5 into mixer 6, intowhich the BFs is introduced through line 8. Means "to provide mildagitation in mixer 6 may be supplied .if desired, but may be omitted ifthe turbulence of flow is :suificient to secure substantially uniformmixing. On introduction of the BFs reaction begins and proceeds rapidlyto completion with formation of a sludge composed largely of thedeleterious components of the petroleum fraction. The sludge-containingfraction passes through line 9 into separator in, sludge being removedtherefrom through line H and the refined fraction through line I2. I50-butane formed from the tertiary butyl fluoride is removed from theseparator through line 13. The refinedfractionpasses into tower I 4wherein it is treated to remove any entrained acid gases such as bywashing with water, the water being introduced into tower I4 throughline I5. Refined product is removed through Hi and the used waterthrough line [8. The refined product may be dried and further treated asdesired. Sludge from separator 10 passes throughline H into distillationzone t9, and BE; and HF are evolved therefrom. BF: is recycled to theprocess through lines 2-0 and 8. HF passes through line 21 into reactor.22 wherein it is reacted'with isobutylene supplied through line 24 toform tertiary butyl fluoride, which is introduced into the processthrough lines 25 and 2. Residue from distillation zone I9 is removedthrough line 26 and may be employed as f-uel'or as a'component ofcompositions useful for example, in paving roads and the like.

The quantity of reactants to employ and the various operating conditionsare advantageously maintained as heretoforedescribed.

The following examples illustrate preferred embodiments of the presentinvention:

It was desired to prepare an .oil suitable for use in transformers froma petroleum fraction obtained from East :Texas crude, .the fractionhaving a viscosity at of 59 Saybolt Universal, .a :flash point of 280 E,and at 10 2mm. of mercuryaninitia'liboiling point :of 274 F., 'a.50%distillation point at :3 61 .F., :and 2.11 .end point of 495 F. .Thearomatic .content of :the fractionrwas composed substantially entirelyof non-.alkylatable aromatics.

The procedure employed'was as .follows:

The fraction and tertiary butyl fluoridewereintroduced into a reactor.and the temperatureadjusted to and maintained at C. by immersion :in awater bath. Boron fluoride under pressure was introduced into the:stirred solution to an initial pressure of 1501p. s. i.,.and-two tofour subsequent additions thereof were made to give a final pressure asindicated 'in Table '1. On completion 'thetoil was filtered, treatedwith ammonia and refiltered to give the final product. Oil :ad hering tothe contactor was recovered and included in the final product.

Quantities of reactants, operation variables, and properties of productsare included in'Table 1. All runs were made at 25C. In each run thealkyl fluoride was converted to the corresponding 'parafiin, namely,isobutane. In all tables parts means parts by weight.

Table 1 Aromatic t-Butyl Contact Refined Sludge Sligh 1 Oxrdatwn O. Dggg fluoride 5 Time z gs Oil formed Oxidation z ffi Sludge Color D(parts) p (minutes) (parts) (parts) Value Value days) Percent) 7. 80 Y30 80 97. 6 3. 90 9. 3 19 4. 50 40 140 96. 2 3. 80 4. 16 5. 70 40 132 1.5 14 9.13 40 135 91. 0 17.0 0.2 9 l. 98 36 99. O 0. 25 18. 9 23 1. 16 8599. 8 0.91 23 2. 40 50 120 97. 5 0. 94 17. 9

l Methoddescrlbed in Oil and Gas 1., 24, No. 2, 125, 135 (1925). IDetermined by ASIM D670-42'l, Method B a Method described in Ind. Eng.Chem., Anal: Ed., vol. 6, 23 (1934); measures the absorbance at 525 mu.Values given are absorbanceXlOO 4 Sulfur content of starting materialwas 0.17%, and of treated product was 0.03%.

These data demonstrate that a great improvement in stability and colorof the oil is obtained when treated in accordance with the presentprocess, with only a slight amount of concomitant loss by sludgeformation, that with relatively small amounts of alkyl fluoride thearomatic content is substantially unchanged'whereas with relativelylarge amounts the aromatic content is significantly decreased. The dataalso include several experiments with BFs as the sole refining agent,and while some improvement in the oil was obtained, the results are notcomparable to those obtained with the combination BF's-alkyl fluoride.

The small amount of sludge formed with the relatively small amounts ofalkyl fluoride is composed largely of compounds of the non-hydrocarbonconstituents of the oil, with the polymers of non-alkylatable aromaticsincluded therein when relatively large amounts of the alkyl fluoride areemployed.

It should be further noted that, using oxidation sludge value as thecriterion, it is possible to overtreat the oil, and in such case, it isadvantageous, where oxidationstability is desired, to blend untreatedstock with the overtreated oil. It is especially advantageous to addstock which has been given a light treatment, such as with boronfluoride'and a small amount of alkyl fluoride, or with boron fluoridealone, to the overtreated oil. Good oxidation stability may also beobtained by adding an inhibitor to the overtreated material, which hasbeen found to give excellent response to the known oxidation inhibitors;an example of such inhibitors are the polyalkyl phenols, e. g.,2,6-ditertiarybutyl-4- methylphenol.

In order to illustrate the value of blending, 25% by volume of thematerial having an oxidation sludge'value (Table 1) of 0.085 was blendedwith by volume of the material having a value of 0.129. The oxidationsludge value for the blend was 0.075, which is lower than for either ofthe constituents. In general, it is advantageous to blend from about 0.1to 10 parts of treated oil with 1 part of untreated, or lighter treated,oil.

EXAMPLE 2 The procedure of Example 1 was followed in the refining of acable oil stock. The temperature employed was 75 C., at whichtemperature the reaction mixture is in a fluid state.

The cable oil stock consisted of the highest boiling fraction of avacuum distillation of the lubricating oil range of East Texas crudepetroleum, having a viscosity of 931.3 centistokes at 100 F. and 22.99at 210 F., and a viscosity index of -55.

The details of preparation are shown in Table 2, and the properties ofthe products, and blends thereof, in Table 3. In each run the alkylfluoride was converted to the corresponding paraffin.

Table 2 t-Butyl Contact Finished Sludge Test Number 2 2 fluoride 23 Timeg g Oil Formed p (parts) p (minutes) (parts) (parts) 100 2. 61 3. 78 4075 100 2. 53 3. 72 40 92. 2 100 2. 66 4. 03 40 95. 8 5. 5 5. 20 40 93. 6100 5. 68 4. 70 65 110 91. 6 100 5. 86 2. 41 40 1 8o. 1 100 6. 07 4. 6940 105 z 100 6. 32 2. 93 145 85 97. 2 2 100 6. 40 2. 44 6O 70 93. 2 1007. 0 3. 37 90 65 96. 3 100 10. 9 9. 35 30 87. 9 100 1].. 0 9. 10 40 1251 65. 1 100 11. 1 6. 73 40 75 1 64. 7 100 11. 1 9. 70 40 105 72. 0

1 Some loss of product occurred.

5 Process carried out in a .Table 3 Resistivi ty l Refractive (ohms/cm.

Viscosity Power Factor (centistokes) I NPA Color Index m Initial :Aged r1 Numbersrefer to the product prepared, or blends thereof, under the 2Table l,-footnote 3.

3 Aged 96 hours in an open beaker at 115 C.

4 Untreated stock.

The data of Tables 2an'd 3 show the value of the present process for theproduction of oils having excellent electrical properties. The ini- 2tial and aged resistivity and power factor, for untreated oil (stock)could not be measured because of its extreme unsuitability as electricaloil; the resistivity thereof is very low and power factor very high.

EXAMPLE 3 A lubricating oil, grade, was treated with 0.53% by weight oftertiary butyl fluoride and an excess of boron fluoride at a temperatureof 75 (3., the procedure being in accordance with Example f1. I p

I To both treated and untreated oil was added /2 by weight ofacommercially available oxidation inhibitor. Both of the inhibited oilswere admixed with an iron oxidation catalyst and heated for 24* hours atF. Properties of the oils before and after the heating" were compared.

It was found that the average percent viscosity increase of theuntreated oil was 52 ascompared to 38.5 for the treated oil; the averagepercent of n-pentane insoluble material of untreated oil was 1.98 ascompared to 1.10 for the treated oil; and that deposition from theuntreated oil was heavy as compared to light depositionfrom the treatedoil.

The process of the present invention isespecially suitable for thepreparation of petroleum oils intended for purposes which require highstability, 1. e., non -sludging properties. Oils which require highstability include electrical oils such as transformer, capacitor, andcable oils, and the other oils such as motor, turbine, and refrigeratoroils. The present process may be operated using batch or continuousoperation.

The separation of aromatic from non-aromatic hydrocarbons in the absenceof non-hydrocarbons is not included within the scope ofthe presentclaims, but is described and claimed in aforesaid copending applicationSerial N 0. 173,748, filed July 14, 1950.

The invention claimed is:

1. Process of refining hydrocarbons which comprises reacting a mixtureof hydrocarbons and non-hydrocarbons with boron fluoride and a tertiaryaikyl mono-fluoride as the sole refining agents, said boron fluoride andsaid tertiary alkyl mono-fluoride being brought together only in thepresence or said mixture of hydrocarbons and non-hydrocarbons, wherebysaid non-hydrocarb'ons are converted to a sludge, and separating saidsludge from the reaction mixture.

2.- Process for the separation of non-hydrocarbone from petroleumcontaining the same which comprises reacting petroleum containing nonhydrocarbons with boron fluoride and a tertiary corresponding testnumberof Table 2 (first colmn) alkyl mono-fiuoride as the sole refiningagents, said boron fluoride and said tertiary alkyl monofl'uoride beingbrought together only in the presence of said petroleum containingnon-hydrocarbons, whereby said non-hydrocarbons are converted to asludge, and separating said sludge fromthe; reaction mixture.-

3*. Process for refining a petroleum fraction containing nonhydrocarbons which comprises reacting saidpetroleum fraction containingnon-hydrocarbons with boron fluoride and a tertiary alkyl mono fluorideas the sole refining agents,- said boron fluoride and said tertiaryalkyl monofluoride being brought together only in the presence of saidpetroleum fraction containingnonhydrocarbons; whereby said nonhydrocarbons are convertedto a sludge, and separating said sludge fromthe reaction mixture.

4. Process according to claim 3 wherein the quantity of the alkylfluoride employed is from o.5 to 2 percent by weight.

5. P'rocess. according to claim 3 wherein the alkylfluoride is atertiary butyl fluoride.

6. Process according to claim 3 wherein the alkyl fluoride is2-fiuoro-2-methylbutane.

'7. Process for the refining of a lubricating oil fraction containingnon-hydrocarbons which comprises reacting said lubricating oil fractioncontaining non-hydrocarbons with boron fluoride and a tertiary alkylmono-fluoride as the sole refining agents, said boron fluoride and saidtertiary alkyl mono-fluoride being brought together only 0 in thepresence of said lubricating oil fraction containing non-hydrocarbons,whereby said nonhydroca'rbons are converted to a sludge, and separatingsaid sludge fromthe reaction mixture.

8. Process according to claim '7 wherein the quantity of the alkylfluoride employed is from 0.5 to 2 percent by weight.

9. Process according to claim 7 wherein the alkyl fluoride is tertiarybutyl fluoride.

10. Process for refining a kerosene fraction containing non-hydrocarbonswhich comprises reacting said kerosene fraction containingnonhydrocarbons with boron fluoride and a tertiary alkyl mono-fluorideas the sole refining agents, said boron fluoride and said tertiary alkylmonofluoride being brought together only in the presence of saidkerosene fraction containing nonhydrocarbons, whereby saidnon-hydrocarbons are converted to a sludge, and separating saidsludgeirom the reaction mixture.

11. Process according to claim 10 wherein the quantity of alkyl fluorideemployed is from 0.5 to 2 percent by weight.

12. Process according to claim 10 wherein the all z'yl fluoride is atertiary butyl fluoride.

13. Process for refining a gasoline fraction con tainingnon-hydrocarbons which comprises reacting said gasoline fractioncontaining nonhydrocarbons with boron fluoride and a tertiary alkylmono-fluoride as the sole refining agents, said boron fluoride and saidtertiary alkyl monofluoride being brought together only in the presenceof said gasoline fraction containing nonhydrocarbons, whereby saidnon-hydrocarbons are converted to a sludge, and separating said sludgefrom the reaction mixture.

14. Process according to claim 13 wherein the quantity of alkyl fluorideemployed is from 0.5 to 2 percent by weight.

15. Process according to claim 13 wherein the alkyl fluoride is tertiarybutyl fluoride.

16. Process for refining a petroleum fraction containing saturatednon-aromatic hydrocarbons, non-hydrocarbons, and aromatics whichcomprises reacting said fraction with boron fluoride and a tertiaryalkyl mono-fluoride as the sole refining agents, said boron fluoride andsaid tertiary alkyl mono-fluoride being brought together only in thepresence of said etroleum fraction, whereby said non-hydrocarbons andsaid aromatics are converted to a sludge, and separating said sludgefrom the reaction mixture.

17. Process according to claim 16 wherein the quantity of alkyl fluorideemployed is in excess of that required to remove the non-hydrocarbons,and is less than the quantity required to remove all of the aromatics.

18. Process according to claim 17 wherein the quantity of alkyl fluorideemployed is from about 2 to 30 percent by weight.

19. Process for the preparation of a refined petroleum fraction stableagainst oxidation which comprises dividing a petroleum fraction andreacting a portion thereof with boron fluoride and a tertiary alkylmono-fluoride as the sole refining agents, said boron fluoride and saidtertiary alkyl mono-fluoride being brought together only in the presenceof said portion of said petroleum fraction, whereby non-hydrocarboncomponents of said portion are converted to a sludge, separating theso-formed sludge from said portion, and blending the so-treated portionwith the untreated portion of said fraction.

20. Process for the preparation oi. a refined petroleum fraction stableagainst oxidation which comprises dividing a petroleum fraction andreacting a portion thereof with boron fluoride and a tertiary alkylmono-fluoride as the sole refining agents, said boron fluoride and saidtertiary alkyl mono-fluoride being brought together only in the presenceof said portion of said petroleum fraction, whereby non-hydrocarboncomponents of said portion are converted to a sludge, separating theso-formed sludge from said portion, subjecting the remaining portion ofthe fraction to a similar but lighter treatment, and blending the twoso-treated portions.

21. Process for the preparation of a refined petroleum fraction stableagainst oxidation which comprises dividing a. petroleum fraction andreacting a portion thereof with boron fluoride and a tertiary alkylmono-fluoride as the sole refining agents, said boron fluoride and saidtertiary alkyl mono-fluoride being brought together only in the presenceof said portion of said petroleum fraction, whereby non-hydrocarboncomponents of said portion are converted to a sludge, separating theso-formed sludge from said portion, subjecting the remaining portion ofthe fraction to the action of boron fluoride as the sole refining agent,separating sludge formed by the latter treatment, and blending the twosotreated portions, whereby a refined petroleum fraction of enhancedoxidation stability is produced.

22. Process for the refining of a lubricating oil fraction containingnon-hydrocarbons which comprises reacting said lubricating oil fractionwith boron fluoride and tertiary butyl fluoride as the sole refiningagents, said boron fluoride and said tertiary butyl fluoride beingbrought together only in the presence of said lubricating oil fractioncontaining non-hydrocarbons, whereby said non-hydrocarbons areconvertedL to a sludge and said tertiary butyl fluoride is converted toisobutane, and separating said sludge and said isobutane from thereaction mixture.

ROBERT M. KENNEDY. ABRAHAM SCHNEIDER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,162,682 Terres June 13, 1939 2,267,730 Grosse et a1 Dec. 30,1941 2,343,744 Burk Mar.7, 1944 2,343,841 Burk Mar. 7, 1944 2,357,495Bloch Sept. 5, 1944 2,378,762 Frey June 19, 1945 2,408,173 MatuszakSept. 24, 1946 2,472,908 Linn June 14, 1949 2,507,599 Cade May 16, 1950

1. PROCESS OF REFINING HYDROCARBONS WHICH COMPRISES REACTING A MIXTUREOF HYDROCABON AND NON-HYDROCARBONS WITH BORON FLUORIDE AND A TERTIARYALKYL MONO-FLUORIDE AS THE SOLE REFINING AGENTS, SAID BORON FLUORIDE ANDSAID TERTIARY ALKYL MONO-FLUORIDE BEING BROUGHT TOGETHER ONLY IN THEPRESENCE OF SAID MIXTURE OF HYDROCARBONS AND NON-HYDROCARBONS, WHEREBYSAID NON-HYDROCARBONS ARE CONVERTED TO A SLUDGE, AND SEPARATING SAIDSLUDGE FROM THE REACTION MIXTURE.